According to a first aspect of the present invention there is provided a trigger pump dispenser comprising: a body; an outlet nozzle; a pump chamber; a piston for defining a variable volume in the pump chamber and movable between a retracted position of larger chamber volume and an inserted position of lesser chamber volume; a trigger coupled with the piston and movable between a starting position at which the piston is in the retracted position and a depressed position at which the piston is in the inserted position; biasing means for biasing the trigger towards its retracted position; an inlet port and an outlet port defined by the body and adapted to be in communication with the pump chamber; an inlet valve adapted to close the inlet port when liquid to be dispensed is in the pump chamber and the piston is moved from the retracted position to the inserted position as the pump chamber decreases in volume, the inlet valve being adapted to open the inlet port when liquid to be dispensed is drawn into the pump chamber through the inlet port as the pump chamber volume increases when the piston is moved from the inserted position to the retracted position, and an outlet valve adapted to open the outlet port when the pump chamber decreases in volume as liquid therein is dispensed through the outlet port and adapted to close when the pump chamber increases in volume, the outlet valve comprising a precompression valve operable to allow liquid through the outlet only after a predetermined elevated pressure is established in the pump chamber, the valve having a movable valve member carried on or by a spring member which biases the valve member to a closed position but flexes in response to the elevated pressure in the chamber acting on the valve member to move the valve member to an open position so that liquid can pass from the chamber and thereafter be dispensed through the outlet nozzle.
This aspect of the invention therefore provides a precompression function in a pumping cylinder of a trigger sprayer which only allows pressurised liquid to be expelled when the pressure of the liquid in the cylinder is above a certain predetermined level. The precompression system can be used to prevent fluid from being discharged at too low a pressure and allows for an improved spraying pattern as liquid can be pressed out of an outlet nozzle at a predetermined and relatively high pressure.
The spring valve member may comprise a flexible annulus which can carry the movable valve member and flex once the predetermined elevated pressure is reached to allow the movable valve member to move to its open position and thereafter return the member to the closed position when the elevated pressure state in the chamber is removed at the end of the pressure stroke.
The valve body member may be inflexible. In other words, it is the spring valve member which flexes in order to move the valve member rather than that valve member itself flexing.
According to an alternative aspect of the present invention there is provided a trigger pump dispenser comprising: a body; an outlet nozzle; a pump chamber; a piston for defining a variable volume in the chamber and thereby pumping liquid into and out of the chamber for dispensing through the outlet nozzle; a trigger coupled with the piston and movable to cause the piston to pump liquid; and biasing means for biasing the trigger to a retracted position, where the nozzle is movable between a first position in which it is in fluid communication with the pump chamber and a second position in which fluid communication is blocked, the pump comprising child-resistant locking means for locking the nozzle in the second position and which must be released to allow movement to the first position.
This aspect of the present invention therefore provides a safety feature which can lock the trigger pump in a closed position in which liquid cannot be dispensed through the outlet nozzle. A child-resistant feature is provided on the pump, for example on the nozzle itself, which must be disengaged before the nozzle can be moved to a position in which liquid can be dispensed there through.
In one embodiment the locking means comprises a resilient member provided on the nozzle and movable between a locked position and an unlocked position. The combination of a requirement for the locking means to be disengaged as well as the nozzle to be moved to the second position can be used to provide an effective child-resistant feature.
According to a further aspect there is provided a trigger pump dispenser comprising: a body; an outlet nozzle; a pump chamber; a dispensing passage; a piston for defining a variable volume in the chamber and thereby pumping liquid into and out of the chamber for dispensing through the nozzle via the dispensing passage; a trigger coupled with the piston and movable to cause the piston to pump liquid; biasing means for biasing the trigger to a retracted position; and a shroud, where the nozzle is movable between a first ‘on’ position in which it is in fluid communication with the dispensing passage and a second ‘off’ position in which fluid communication is blocked, the nozzle having indicator means carried on or by the nozzle body which are alternatively brought into register with windows on the shroud to indicate if the nozzle is in the ‘on’ or ‘off’ position.
Aspects of the present invention and embodiments thereof may be provided in combination with a container.
Aspects and embodiments of the present invention may be used separately or in combination.
The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: